Noise pollution disrupting sea life

November 8 2002By Peter Huck

The world's ocean habitats, already stressed by over-fishing, pollution, and global warming, are far from silent. While the sound level caused by waves in empty seas is 80 decibels, human activity - supertanker engines, or guns fired at the seabed during oil exploration - often exceeds 180 decibels. This is 10 billion times louder on the geometric decibel scale. Whales shy away from sounds over 120 decibels. Underwater sounds can travel vast distances; an explosion off Australia was once detected in Bermuda. Sound travels five times faster in water and is used by whales to communicate, navigate, and find mates and food. Scientists believe noise pollution causes whales to change their migration patterns and disrupts their love songs.